1. Field of the Invention
The present invention is generally directed to paint brushes, and more particularly, to paint brushes having groups of bristles of differing stiffnesses.
2. Description of the Prior Art
Many types of paint brushes are known in the art. Some of these brushes use bristles of varying length. U.S. Pat. No. 4,144,611 to Brown disclosed a paint brush designed to draw very fine lines. Short mink hairs are gathered to form the core of the brush and longer mink hairs are dispersed outside of the shorter ones. In order to paint very fine lines, the longer hairs are separated from each other and the shorter hairs. U.S. Pat. No. 4,088,413 to Rossignol de la Ronde discloses a liner brush having a central and a peripheral tuft of hair in which the central tuft projects beyond the peripheral tuft. The central and peripheral tufts may be of different materials or have different stiffness. The central tuft is the only portion used to draw thin lines and the peripheral tuft serves as a reservoir to store the material being applied.
Other types of paint brushes use bristles of different stiffnesses. U.S. Pat. No. 3,047,898 to Levite discloses a brush containing several longitudinal rows of bristles of different characteristics. More specifically, fine natural bristles are adjacent to coarse boar bristles. U.S. Pat. No. 1,694,364 to Albright discloses a shaving brush in which a cup-like depression is formed in the ends of the bristles for the purpose of retaining shaving cream. The core of the brush is constructed of relatively stiff bristles such as pig bristles and the outer bristles surrounding the core of the brush are composed of soft badger hair.
Other patents in the art are U.S. Pat. No. 4,627,125 to Gruns which discloses a paint brush which has a set of guide bristles and main bristles. The guide bristles are shorter in length than the main bristles and serve the purpose of being a visual aid to help prevent the painter from dipping the paintbrush too deeply into the paint. U.S. Pat. No. 4,483,036 to Sayklay discloses an artist's paint brush helpful in painting leafy vegetation such as trees by providing a plurality of tiered bristles each layer containing bristles of various length. The various length bristles are arranged to form a plurality of furcations. U.S. Pat. No. 4,610,045 to Rauch and U.S. Pat. No. 3,295,156 to Brant disclose toothbrushes with various length bristles. U.S. Pat. No. 4,091,490 to Allen discloses a skin cleansing device which uses a central tuft of human hair and a shorter peripheral tuft of a textile material. In U.S. Pat. No. 4,454,622 to Poppendieck a fingernail polish brush is disclosed having the hairs around the perimeter of the brush the shortest in length with each successive circle of hairs increasing in length ending with the last round of hairs in the center of the brush being the longest. U.S. Pat. No. 4,153,967 to Thoma discloses a circular polishing and cleaning brush. U.S. Pat. No. 3,237,233 to Adams discloses a rotary brush having soft animal fur and tougher, coarser synthetic fibers for cleaning the peripheral surfaces of rotary metal drums.
One of the major problems with paint brushes used to draw very fine lines is that the brush itself cannot store very much of the paint or other material being applied. Consequently artists need to continually dip the brush in the material to be applied. In the case of a brush designed to draw very fine lines, one might need to redip after every line drawn or to redip if a very long line needs to be drawn. Thus, this creates a great inconvenience to the artist who must interrupt her work to redip thus disturbing her concentration on her work.
Problems are also created when one wants to paint a straight line, especially if one is painting on a surface that is already painted. Typically to draw a straight line one would lay down masking tape and paint along one of its edges. A straight line was never achieved, however, because the paint would bleed under the masking tape thus blurring the line. This problem is compounded when there is already preexisting paint on the canvas because the preexisting paint has microscopic grooves. The prior art paint brushes would not allow the paint to enter the microscopic grooves thus the paint was only applied to the top surface portions of the grooves and a straight line was not drawn.